1. Technical Field Relating to the Invention
The present invention relates to a method for manufacturing an electric film body made by forming a film body to have a shape and a size in accordance with desired electric characteristics.
2. Description of Related Art
In recent years, a resistor or the like is formed in a thin film shape along with a high density trend of a circuit of a wiring board. In addition, the wiring board is multilayered. Examples of this are a circuit board with a capacitor and a multilayered circuit board using the circuit board described in Patent Document 1 (Japanese Patent Laid-Open No. H08-125302) and an element-incorporated multilayered wiring board described in Patent Document 2 (Japanese patent Laid-Open No. 2003-17858).
The multilayered circuit board in Patent Document 1 is a circuit board with a capacitor in which a printed capacitor is formed on a surface of an insulating board. The printed capacitor includes a first electrode made of a copper foil on the surface of the insulating board, a dielectric layer made of a dielectric paste on the first electrode, and a second electrode made of a conductive paint on the dielectric layer.
The element-incorporated multilayered wiring board in Patent Document 2 includes a core base material having formed thereon a first wiring pattern, an insulating layer coated and formed on a side of a surface of the core base material having the first wiring pattern and provided with a closed-end hole for connection, and at least one incorporated element and a second wiring pattern not connected to the incorporated element formed on a surface of the insulating layer. The first and second wiring patterns are electrically connected via the closed-end hole for connection, and the incorporated element is not electrically or magnetically connected to at least any other incorporated element and is configured to enable independent adjustment of characteristics thereof.
In such a board, a wire or the like is formed in the following manner. Here, a thin-film resistor is described as an example of the wire or the like.
A resistor 1 is configured as shown in FIG. 1. A resistor thin film 2 is formed on an organic insulating layer in FIG. 1. This resistor thin film 2 is formed by a photolithographic method or the like. On both ends of the resistor thin film 2 are provided electrodes 4. The electrodes 4 are made of plating or the like.
A method for manufacturing this resistor 1 is shown in FIGS. 2A to 2E and 3. FIGS. 2A to 2E are schematic views showing a manufacturing process of the resistor 1. FIG. 3 is a flowchart showing the manufacturing process of the resistor 1. Hereinafter, the manufacturing process will be described based on FIGS. 2A to 2E while referring to the flowchart in FIG. 3 as needed.
First, as in FIG. 2A, a resistor thin film 7 is formed on the organic insulating layer 3 as a board layer (step S1). Subsequently, as in FIG. 2B, a photoresist layer 8 is formed by photolithography with use of predetermined line width data (line width data calculated theoretically) based on a targeted film thickness (film thickness target) (step S2).
Subsequently, as in FIG. 2C, the resistor thin film 7 is patterned by etching (step S3). Thereafter, as in FIG. 2D, the photoresist layer 8 is removed, and electrodes 9 are formed (step S4). Subsequently, as in FIG. 2E, probes 10 are brought into contact with the electrodes 9, and the electrodes have current applied thereto to measure voltage for confirmation of a resistance value (step S5).
Other wires and the like are formed in a similar manner.